The map is showing a continent (I've still to figure out the exact scale, but from East to West it's about the distance from Cape Finisterre to the Urals), and is at the stage where I'll branch out several maps off of it (a political map, a "geographical overview" map).

The borderstyle I've come up with is this:
31850

And I'm not happy with it. For one, it requires too much work, especially once I add regions to the polities. For another, it doesn't really fit the style of the map, nor the game world it'll belong to (Think "D&D meets the Holy Roman Empire in the late 1500s to early 1600s").

For the border style, I was thinking of just adding a layer with lines similar to the rivers from an effect POV, except with different colours (which I want to keep limited, before I overload the map), and that's that.

With labeling, I'm kinda stumped, too, since GIMP's text capabilities are more infuriating than helping.

Of course, I could import the map into Inkscape, and play with Inkscape's tool set...

So, what say ye?

Keep in mind I'm still a novice in GIMP and (fantasy) mapping, and my head hurts from the thinking. ;)

Known bugs: No tributaries for the rivers. The Tapered Stroke script by RobA decided to break on this image (moving the stroke a couple of pixels in +y direction), and I couldn't be bothered yet to tweak brush styles to fake 'em.